[4] During his junior year, Giesler was a backup to Mike Kenn at the offensive left tackle position and started two games for the 1977 Michigan Wolverines football team.
[6] As a senior, Giesler started all 12 games at left tackle for the 1978 Michigan Wolverines football team that compiled a 10–1 regular season record, won the Big Ten Conference championship, and lost to USC in the 1979 Rose Bowl.
[1] As a rookie during the 1979 NFL season, Giesler did not start any games for the Dolphins, played on special teams and was also a backup to veteran linemen Bob Kuechenberg and Mike Current.
In June 1984, Giesler rejected an offer to play for the Michigan Panthers in the United States Football League (USFL) for a reported $900,000 over three years.
[14] Giesler considered retiring prior to the 1988 season and conducted a two-month holdout before signing a two-year contract with the Dolphins for a reported $657,500.